Portable hand-held device with a biosensor

ABSTRACT

The invention pertains to a portable hand device with biosensor for the investigation of biological fluids such as whole blood, liquor, urine and serum. It is characterized by a securely fixed electrode, which is covered by a replaceable biomembrane, as reservoir bag containing system solution and a waste bag, a pump, a tube transport system, an operating lever with a valve function, three operating elements, a display, and a control unit signal capture and overall procedure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention concerns a hand-held equipment for the examination ofbiological liquids such as whole blood, liquor, urine and serum with theaid of electrochemical biosensors without costly preceding analysisbeing carried out.

2. Description of the Related Art

For a fairly long time biosensors have been applied as sensitive andselective detection methods in analysis, in particular of medicaldiagnostics. For this purpose, respective biosensors are installed inanalyzers which allow to carry out a fast inexpensive and notably properexamination of the respective parameters in central laboratories wheremany samples have to be examined. This requires, as a rule, a samplethroughput of 80 180/h.

The analyzers are based on various principles. For the most part, theyare operated with a continuous air segmented flow of the respective,highly diluted laboratory samples, i.e. this method requires thepreparation of the solutions to be examined (e.g. whole blood) with adilution of the analysis material being required. It is very costly toanalyze individual samples by means of this equipment as the efficiencyof analyzers becomes effective only in the case of a high number ofsamples being examined (ESAT® 6660 and ECA 180 from Pr{umlaut over(u)}fger{umlaut over (a)}te-Werk Medingen GmbH, EBIO (Eppendorf® fromEppendorf-Netheler-Hinz GmbH).

Furthermore, there are instructions known to measure individual samplesalso without preceding analysis being carried out which, however, arevery immovable owing to a high integrated measuring comfort, thus beingunsuited for a local application (YSI 2300 STAT of YSI Incorporated andSTAT Profile PLUS of NOVA BIOPMEDICAL GmbH).

From EP-A-0 520 443 a portable sensor equipment is known which consistsof a waste collector, liquid canals and intakes and an electrochemicalsensor in a case and an external calibration unit.

For the time being, commercialized mobile systems with integratedbiosensors are too expensive owing to the high measuring comfort(internal calibration), require too much maintenance and are operatedwith too long transport ways for the sample to be measured. For thisreason, in addition to a comparatively high price, delays and pollutionwill result which have detrimental effects on the quality of analyzing.

All measuring systems applied locally to determine parameters such asglucose and lactate are at present based on nonreusable consumables(test strips, photometric; strip electrode, amperometric). Thus theanalysis is determined by the price of the test strip and the test stripis not calibratable as it may be used just once.

BRIEF SUMMARY OF THE INVENTION

That is why it was the task of the invention to provide a technicalsolution for implementing a locally applicable equipment for theexamination of blood, urine, liquor without preceding analysis beingcarried out and a re-usable biosensor which is marked by a low price andalso lowest maintenance costs.

The task will be solved by the construction of a hand-held equipment.

The hand-held equipment consists of a rigidly anchored electrode whichis covered by a replaceable biodiaphragm, equipped with a systemsolution supply bag and a waste bag, a pump, a hose transport system, anoperating lever with valve function, three operating elements, a displayand a control unit for signal recording and the whole process. Theequipment works with a temperature compensation. Thus, modifiedsensitivities of the biosensor are compensated through variations of theambient temperature in the range between 15° C. and 35° C. on the basisof a signal-temperature function. Welded PE foils are preferentiallyused for the system solution and the waste, with the storage volumetotalling approx. ⅓ and the waste volume approx. ⅔ of the total volume.In a preferential variant of execution the two bags are welded with eachother. They are arranged one above the other and disposed jointly uponconsumption of the buffer stock. The bag is opened when being installedthe hand-held equipment through a hollow needle. When putting in a newsupply bag the second half of the PE bag will be empty. In the same wayas the stock will be consumed for purifying the measuring cell the wastebag will be filled. After having consumed the system solution completelythe whole bag will be disposed.

The rigidly anchored electrode is a Pt-Ag/AgCl electrode of a CLARKelectrode type. By combining it with a ready-made biodiaphragm byplacing simply this the electrode is converted into a biosensor whichmay register various substances in accordance with the biomolecule used.

To execute a measurement the operating lever will be changed front idleposition B (9) to position A (10), thus opening the flow system. Byturning the pump into position I the electrode will be put into thestate ready for measurement with the system solution in front of ithaving been sucked off.

The sample to be analyzed will be supplied with adjusting the freshlytaken sample in a capillary tube to the sample opening of the hand-heldequipment which is directly above the biosensor. Subsequently the pumpis set in position II and the sample to be measured is transported by itin front of the biosensor. After effecting the measurement the resultwill be shown on the display and the operator will be requested topurify the system. The capillary tube is taken off by the user. Byputting back the operating lever to position B the purification systemis again closed. Purification itself is effected by turning the pumpslowly until “ready for use” will appear on the display which isregarded to be a confirmation that the purification is completed and thepump will be in position III.

A hose pump is preferentially used as pump.

The three operating elements will be responsible for the followingfunctions:

B1: on/off

B2: menu functions

B3: set key

Power supply will be possible through an internal 9V accumulator as wellas an external solar cell or a supply unit. Depending on the biomoleculeused a biodiaphragm has a limited lifetime which totals, in general, 10to 30 days. The user will be shown the expiry of lifetime on thedisplay. Upon expiry of its service life the biodiaphragm will bereplaced by a new one.

The biodiaphragm is replaced by unlocking the respective sealing cap,taking off the worn-out diaphragm and simply placing a new diaphragm. Bythe information on the display the user will be informed on the stepsnecessary to take until the new diaphragm will be operative.

Signal recording and the whole process are controlled through a controlunit. The whole process involves the beginning of signal recording(start), the end of signal recording, filing and storing of measuredvalues, the calibration of the equipment and display information for theoperator as regards the steps.

The hand-held equipment in conformity with the invention allows to carryout a minimum of 300 measurements without replacing the supply bag. Aspecial advantage is that the equipment is usable in a temperature rangebetween 15° C. and 35° C., independent of its place and time of use. Inaddition, the weight of the equipment is less than 500 g.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in greater detail by means of the followingexamples of execution and drawings.

FIG. 1—Overall view of the hand-held equipment

FIG. 2—Basic diagram of the equipment and arrangement of the supply andwaste bags

FIG. 3—View of electrode arrangement and representation of thereplacement of the biodiaphragm

DETAILED DESCRIPTION OF THE INVENTION

The hand-held equipment in conformity with FIG. 1 serves the examinationof whole blood, liquor, tissue fluid, urine, serum, plasma, food samplesas well as water samples as regards metabolites such as e.g. glucose,lactate; yet also nutrients and products of food and fermentationindustries such as e.g. lactose, ascorbic acid, malic acid and variousamino acids.

In FIGS. 1,2 and 3 the principle process of such a measurement isdemonstrated. With the operating lever 8 opened (A-10) the buffersegment is put in position I (5) by pump 4, a hollow needle with thesample to be analyzed is put into opening 24, pump 4 is put in positionII (6), and thus positioned in sample canal 25 above the biosensor 33 tostart measurement. After completing measurement the measured value willbe shown on the display (1) and the operator is requested to purify thesystem. For this purpose, the hollow sample needle is taken from opening24, the operating lever 8 is put in position B (9) and by turning pump4, the system solution is moved from the supply bag 19 through the hosetransport system 21 into the waste bag. This contact of the biosensorwith the buffer solution results in the purification of the sensor. Theoperator is informed on the termination of the purification by “readyfor use” on display 1. Now, the pump is again put into idle position III(7). Thus, the hand-held equipment will be again ready for measuring andthe following measurement will be effected according to the same scheme.

According to FIG. 3 the biodiaphragm may be again replaced upon expiryof the lifetime of a biomembrane (which is shown the operator on display1). To this end, the operating lever 8 will be drawn upwards throughspring 1 and turned upwards by 90°. Thus, it is possible to swing openby 90° the measuring cell cover 28 on axis 26 by releasing the fixingdevice 29. It is now possible to take off the worn-out biodiaphragm 32and to put a new one on electrode 33 which is equipped with a rubberjoint 34. Thereupon the measuring cell cover will be again swung down,stopped in 29 and the operating lever will be again put in position B(9). Thus the flow system will be again closed and by turning the pumpsystem solution will be put on the biosensor for conditioning.

Reference marks:

1. display

2. plotting unit

3. connection for solar cell or supply unit

4. pump

5. pump position I

6. pump position II

7. pump position III

8. operating lever

9. operating lever—position B

10. operating lever—position A

11. measuring cell with biosensor

12. operating element B1

13. operating element B2

14. operating element B3

15. case

16. accumulator

17. spring for operating lever

18. waste bag

19. supply bag

20. hollow needle (connection between hose system, waste or supply bags)

21. hose system

22. seal for waste bag

23. seal for supply bag

24. sample opening

25. sample canal

26. axis

27. connection with the hose transport system (connection between samplecanal and hose)

28. measuring cell cover

29. fixing device of the measuring cell cover

30. measuring cell bottom

31. connections for electrodes

32. biodiaphragm

33. electrode

34. electrode seal

What is claimed is:
 1. Mobile hand-held equipment with biosensor, inparticular for the local determination of original biological solutions,wherein a case (15), an amperometric biosensor (33) disposed in the case(15), a measuring cell (11) disposed in the case (15), a supply bag (19)and a waste bag (18) for fresh and waste system solution disposed in thecase (15), a pump (4) placed in the case (15), a hose transport system(21) placed in the case (15), a sample opening (24) and a sample canal(25) placed in the case (15), an operating lever with valve function (8)attached to the case (15), equipment for replacing diaphragms (26, 27,28, 29) placed in the case (15), a display (1) mounted to the case (15),on/off key button (12) placed on the case (15), menu function key button(13) placed on the case (15), set key button (14) placed on the case(15), a connector (3) for making a connection to a power supply (16), aunit for signal recording and the whole measuring process (2), andwherein welded PE foil is used for the supply bag (19) and therespective waste bag (18), the two bags are welded with each other,arranged one above the other and will be jointly disposed after thebuffer stock will have been consumed.
 2. Mobile hand-held equipment withbiosensor according to claim 1, wherein the biosensor (33) is arrangeddirectly below the sample opening (24).
 3. Mobile hand-held equipmentwith biosensor according to claims 2 or 1, wherein the pump used (4) isoperated by hand and without using electric energy.
 4. Mobile hand-heldequipment with biosensor according to claims 2 or 3, wherein the powersupply of the electrode may be effected through a chargeable accumulator(16) as well as a solar cell, respectively, for forming a supply unit(3).
 5. Mobile hand-held equipment with biosensor according to claims 2or 1, wherein the weight of the equipment is less than 500 g.
 6. Mobilehand-held equipment with biosensor according to claim 1, wherein thebiosensor includes an electrode covered by a biodiaphragm.
 7. A mobilehand-held equipment with a biosensor comprising a case; a connection forsupplying power attached to the case; an on/off button attached to thecase and connected to the connection for supplying power; a menufunction key button attached to the case and connected to the on/off keybutton; a control unit disposed in the case; a set key button attachedto the case and connected to the control unit; a measuring cell disposedin the case; a pump disposed in the case and connected to the measuringcell and to the menu function key button; a sample opening furnished atthe case; a sample canal furnished at the case and led to the sampleopening; a supply bag for delivering fresh system solution, wherein PE(polyethylene) is used for the supply bag and wherein the supply bagwill be disposed after the system solution has been consumed; a valvedisposed in the case; an operating lever attached to the valve and foractuating the valve; an amperometric biosensor disposed in the measuringcell; a waste bag for receiving discharged waste system solution,wherein PE (polyethylene) is used for the waste bag and wherein thewaste bag will be disposed together with the supply bag after the systemsolution has been consumed; a hose transport system connected to thepump and to the supply bag; equipment for replacing diaphragms disposedin the case; a display disposed in the case and connected to the controlunit; a unit for signal recording and the whole measuring processconnected to the control unit.
 8. The mobile hand-held equipment withbiosensor according to claim 7, wherein the biosensor is arrangeddirectly below the sample opening; wherein the pump used is operated byhand and without using electric energy; wherein welded PE foil is usedfor the supply bag and the waste bag, welded to each other, wherein thesupply bag and the waste bag are arranged one above the other andwherein the supply bag and the waste bag will be jointly disposed afterthe buffer stock will have been consumed; wherein the power supply ofthe electrode is furnished by a chargeable accumulator and by a solarcell forming a supply unit; wherein the weight of the equipment is lessthan 500 g; wherein the sample opening is adapted to receive a capillarytube.
 9. The mobile hand-held equipment with biosensor according toclaim 7, wherein welded PE foil is used for the supply bag and the wastebag, welded to each other, wherein the supply bag and the waste bag arearranged one above the other and wherein the supply bag and the wastebag will be jointly disposed of after the system solution will have beenconsumed.
 10. A mobile hand-held equipment with biosensor comprising acase; an electrode rigidly anchored in the case; a replaceablebiodiaphragm covering the electrode and including a system solutionsupply bag and a waste bag; a pump attached to the case; a hosetransport system attached to the case; an operating lever including avalve function supported at the case; three operating elements attachedto the case; a control unit attached to the case for signal recording; atemperature compensation system for modifying sensitivities of thebiosensor by furnishing compensation through variations of the ambienttemperature the range between 15 degrees centigrade and 35 degreescentigrade on the basis of a signal temperature function.
 11. The mobilehand-held equipment with biosensor according to claim 10 wherein a hosepump performs the functions of the pump.
 12. The mobile hand-heldequipment with biosensor according to claim 10 further comprising anelectrical power supply; an on/off switch attached to the case foractivating an electrical power supply; a menu function switch attachedto the case for selecting operating modes of the mobile hand-heldequipment with biosensor; a set key attached to the case for settingvalues for the operation of the mobile hand-held equipment withbiosensor.
 13. The mobile hand-held equipment with biosensor accordingto claim 12, wherein the power supply is an internal 9 volt accumulator.14. A mobile hand-held equipment with biosensor comprising a case; anelectrode rigidly anchored in the case; a replaceable biodiaphragmcovering the electrode and including a system solution supply bag and awaste bag; a pump attached to the case; a hose transport system attachedto the case; an operating lever including a valve function supported atthe case; three operating elements attached to the case; a control unitattached to the case for signal recording; wherein the system solutionbag is made of polyethylene and wherein the waste bag is made ofpolyethylene; wherein the storage volume is approximately one third ofthe total volume and wherein the waste volume is approximately one thirdof the total volume; wherein the electrode is a Pt-Ag/AgCl electrode ofa Clark electrode type.
 15. A method for operating a hand-held-equipmentwith biosensor comprising installing a system solution supply bag in ahand-held equipment; opening the system solution supply bag with aneedle; installing a waste bag in the hand-held equipment; opening thewaste bag with a needle; consuming the system solution supply forpurifying a measurement cell; installing a replacement system solutionsupply bag when the currently installed system supply bag issubstantially empty; filling the waste bag in the same way as the systemsolution supply is being consumed from the system solution supply bag;covering the electrode with a biodiaphragm and thereby converting theelectrode into a biosensor, which registers various substances inaccordance with the biomolecule used by combining a Pt-Ag/AgCl electrodeof a Clark electrode type covered with a ready made biodiaphragm. 16.The method for operating a hand-held-equipment with biosensor accordingto claim 15, further comprising changing an operating lever from an idleposition (B) to an operating position (A); opening thereby the flowsystem; turning a pump into a first position; putting thereby theelectrode into a state ready for measurement; sucking off systemsolution in front of the electrode; adjusting a freshly taken sample ina capillary tube to a sample opening of the hand-held equipment, whereinthe sample opening is disposed immediately above the biosensor; turningthe pump into a second position; transporting the sample to be measuredwith the pump in front of a biosensor; performing a measurement;displaying a result on a display; requesting the operator to purify thesystem; manually taking off the capitary by the user; returning theoperating lever into the idle position (B) and thereby closing thepurification system.
 17. The method for operating a hand-held-equipmentwith biosensor according to claim 16, further comprising turning thepump slowly into a third position until “ready for use” appears on thedisplay and thereby effecting purification; displaying an expiry oflifetime of a power supply on the display; unlocking a respectivesealing cap for replacing the biodiaphragm; removing a worn-outbiodiaphragm; placing a new biodiaphragm.
 18. The method for operating ahand-held-equipment with biosensor according to claim 15, furthercomprising opening an operating lever; putting a buffer segment into afirst position by a pump; placing a hollow needle with a sample to beanalyzed into an opening; putting the pump into a second position;thereby positioning the sample in a sample canal above the biosensor;starting a measurement; completing the measurement; showing ameasurement value on a display; requesting the operator to purify thesystem; taking the hollow needle from the opening; putting the operatinglever into an idle position; turning the pump; moving thereby systemsolution from a supply bag through a hose transport system into a wastebag; purifying the biosensor by contacting the biosensor with a buffersolution; informing the operator about the termination of purificationby a signal “ready to use” on a display; placing the pump into a thirdidle position.
 19. The method for operating a hand-held-equipment withbiosensor according to claim 15, further comprising replacing abiodiaphragm upon expiration of the lifetime of a biomembrane; drawingthe operating lever upwards through a spring; turning the operatinglever upward by 90 degrees; swinging a cover of the measuring cell openby 90 degrees around an axis; releasing a fixing device; taking off aworn-out biodiaphragm; putting a new biodiaphragm on the electrodeequipped with a rubber joint; swinging the cover of the measuring celldown again; stopping the cover of the measuring cell; placing theoperating lever again in an idle position; thereby closing again theflow system; turning the pump; thereby putting system solution on thebiosensor for conditioning.
 20. A mobile hand-held equipment withbiosensor comprising a case; an electrode rigidly anchored in the case;a replaceable biodiaphragm covering the electrode and including a systemsolution supply bag and a waste bag; a pump attached to the case; a hosetransport system attached to the case; an operating lever including avalve function supported at the case; three operating elements attachedto the case; a control unit attached to the case for signal recording;wherein welded PE foil is used for the supply (19) and the respectivewaste bags (18), the two bags are welded with each other, arranged oneabove the other and will be jointly disposed after the buffer stock willhave been consumed.
 21. Mobile hand-held equipment with biosensor, inparticular for the local determination of original biological solutions,wherein a case (15), an amperometric biosensor (33) disposed in the case(15), a measuring cell (11) disposed in the case (15), supply (19) andwaste bags (18) for fresh and waste system solution disposed in the case(15), a pump (4) placed in the case (15), a hose transport system (21)placed in the case (15), a sample opening (24) and a sample canal (25)placed in the case (15), an operating lever with valve function (8)attached to the case (15), an equipment for replacing diaphragms (26,27, 28, 29) placed in the case (15), a display (1) mounted to the case(15), on/off key button (12) placed on the case (15), menu function keybutton (13) placed on the case (15), set key button (14) placed on thecase (15), a connector (3) for making a connection to a power supply(16), consisting of an accumulator and a solar cell or another supplyunit, a plotting unit for signal recording and the whole measuringprocess (2), and wherein welded PE foil is used for the supply (19) andthe respective waste bags (18), the two bags are welded with each other,arranged one above the other and will be jointly disposed after thebuffer stock will have been consumed.
 22. A method for operating ahand-held-equipment with biosensor comprising installing a supply/wastesystem, consisting of a supply bag welded with a waste bag; opening bothbags with a needle; consuming the system solution supply for purifying ameasurement cell; exchanging the supply waste system, when the currentlyinstalled system is nearly empty, which is indicated by a displayreading; covering the electrode with a biodiaphragm and therebyconverting the electrode into a biosensor, which registers varioussubstances in accordance with the biomolecule used by combining aPt-Ag/AgCl electrode of a Clark electrode type covered with a ready madebiodiaphragm.